How do they make Verilog code for unknown ICs?

Guy Sotomayor Jr ggs at
Mon Jun 20 15:03:44 CDT 2016

What you can do (and I’ve seen it done) is define verilog modules that
provide the functions of the IC and use that in their designs.  I’ve seen
at least two interesting classic computer recreations using this approach
(re-implemenation of the CADR lisp machine in verilog and an IBM 360/30
in verilog).

ROMs are easy (just instantiate a lookup table).  PLCs are just combinatorial
equations which are relatively easy with the verilog “assign” statement.

TTFN - Guy

> On Jun 20, 2016, at 12:35 PM, Swift Griggs <swiftgriggs at> wrote:
> In my recent studies of electronics (I'm a noob for all practical 
> purposes) I keep seeing folks refer to Verilog almost as a verb. I read 
> about it in Wikipedia and it sounds pretty interesting. It's basically 
> described as a coding scheme for electronics, similar to programming but 
> with extras like signal strength and propagation included. Hey, cool! 
> Why are folks referring to "Verilogging" and "doing a verilog" on older 
> chips. Is there some way you can stuff an IC into a socket or alligator 
> clip a bunch of tiny leads onto it and then "map" it somehow into Verilog? 
> Is that what folks who write emulators do? Ie.. they exhaustively dump 
> Verilog code for all the chips then figure out how to implement that in 
> some computer programming language like C ? What do folks do for ROM chips 
> and PLCs? I'd think they must dump the code and disassemble it. No? 
> I'm just curious and this is a tough question to answer with Google since 
> I'm pretty clueless and don't know the right words to search for. I notice 
> people talk about correcting their Verilog code, so it must be somewhat of 
> a manual process. I'm just wondering how someone even gets started with a 
> process like that. 
> -Swift

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